2010015810
Level:
B
The picture shows a square pyramid. The side of a base square is
\(a = 10\; \mathrm{cm}\) and the height of
the pyramid is \(v = 10\; \mathrm{cm}\).
Find the angle \(\varphi \) between the lateral edge and the edge of the base of the pyramid.
\(\mathop{\mathrm{tg}}\nolimits {\varphi} = \sqrt5
\mathrel{\implies }\varphi \mathop{\mathop{\doteq }}\nolimits 65^{\circ }54^{\prime}\)
\(\mathop{\mathrm{tg}}\nolimits \varphi = \frac{\sqrt5}
{5}\mathrel{\implies }\varphi \mathop{\mathop{\doteq }}\nolimits 24^{\circ }6^{\prime}\)
\(\mathop{\mathrm{tg}}\nolimits \frac{\varphi}{2} = \frac{\sqrt5}
{5}\mathrel{\implies }\varphi \mathop{\mathop{\doteq }}\nolimits 48^{\circ }11^{\prime}\)
\(\mathop{\mathrm{tg}}\nolimits {\varphi} = \frac{\sqrt{10}}
{2}\mathrel{\implies }\varphi \mathop{\mathop{\doteq }}\nolimits 57^{\circ }41^{\prime}\)